Freely quoting from Leon’s page:
Below is a collection of games and other programs written in BASICA that also run on GWBASIC. Some are programs I wrote myself; a whole bunch are type-in programs from David Ahl’s Basic Computer Games series of books, and a few are from other sources… Enjoy!
GWBASIC is the successor to IBM’s BASICA. The original IBM PC shipped with three versions of BASIC: Cassette, Disk, and Advanced (“BASICA”). Cassette BASIC came on the computer ROM, so if you turned on the machine with no disk in the drive, the computer booted directly into Cassette BASIC, not DOS (unless I’m remembering this wrong). Advanced BASIC included more commands than Disk BASIC, including PLAY [music] and [draw] CIRCLE. These versions of BASIC were dependent on the IBM PC ROM, so they won’t work on modern computers. GWBASIC is free of that limitation, and will run inside DOSBox …
See also related previous discussions: